Northern Thai

Letters

Combining marks

Numbers

Punctuation

Other

Vowel sounds

Consonant sounds

	labial	alveolar	post- alveolar	palatal	velar	glottal
stops	p b	t d			k	ʔ
aspirated	pʰ	tʰ
affricates			t͡ɕ
fricatives	f	s			x	h
nasals	m	n		ɲ	ŋ
approximants	w	l		j

The glottal stop is pronounced after short open vowels. An initial glottal stop is also pronounced before independent vowels (see standalone).

Tone

The Chiang Mai dialect of Northern Thai has 6 tones. They are illustrated in fig_tones, which is taken from Wikipedia.

Wikipedia provides the following information for the 6 phonemic tones for unchecked syllables in the Changmai dialect of Northern Thai. (It also has sound recordings.)wnl,#Consonants

This is the list for checked syllables.wnl,#Consonants

The mapping of tones to characters is described in tones.

Structure

See Tai Tham/Khün.

Vowel summary table

The following table summarises the main vowel to character assigments.

ⓘ represents the inherent vowel. Diacritics are added to the vowels to indicate nasalisation (not shown here). Standalone vowels are shown in the right-hand column.

For additional details see vowel_mappings.

The following is the set of characters needed to write vowels, as described in this section, grouped by general category.

Inherent vowel

ᨠ ka U+1A20 LETTER HIGH KA

a following a consonant is not written, but is seen as an inherent part of the consonant letter, so ka is written by simply using the consonant letter.

Post-consonant vowels

Vowels following consonants written using 19 combining marks and 3 consonant letters (2 of which as subjoined forms). Unlike Thai and Lao, all vowel signs are combining marks, and are stored after the base character. Vowels are often written differently when they appear in a closed vs. open syllable. There are 5 pre-base vowel signs, but no circumgraphs.

This page lists 29 multipart vowels (made from 9 vowel signs, and 3 consonants/diacritics). Multipart vowels can involve up to 5 glyphs, which can surround the base consonant(s) on up to 4 sides.

Pre-base vowel signs

ᨠᩮ keː U+1A20 LETTER HIGH KA + U+1A6E VOWEL SIGN E

ᩮ␣ᩰ␣ᩯ␣ ␣ᩱ␣ᩲ

Five vowel signs appear to the left of the base consonant letter or cluster.

show composition

ᨯᩱ᩶

These combining marks are stored after the base consonant: the rendering process places the glyph before that of the base consonant. However, the Unicode Consortium is currently examining the coding model for Tai Tham. There is a possibility that pre-base vowel signs may be stored before the consonant in future. Also, some fonts already require this kind of handling, especially for dealing with complex combinations of characters.

Standalone vowels

In Northern Thai standalone vowel sounds can be written in 2 different ways.

Tones

With the high/low categorisation of consonants, Northern Thai writing generally needs only the two combining tone marks below to indicate one of the possible phonetic tones.

If there is a vowel over or below a consonant or consonant stack, the tone mark follows the vowel in storage, and is displayed above or alongside the vowel.

Otherwise, the tone is input after the consonant, ie. before a vowel sign that is displayed to the right or below, and appears over the consonant. e

The default fonts used here expect the tone to be typed after a lefted vowel if there is one; after a vowel above, if there is one; before a vowel to the right; and doesn't seem to matter wrt low vowel. See this test. Noto agrees except for lefted vowels.

The following chart shows how to tell which tones are associated with a syllable.

Vowel sounds mapped to characters

This section maps Northern Thai vowel sounds to common graphemes in the Lanna orthography.

The left column shows dependent vowels in open syllables, the middle column shows dependent vowels in closed syllables, and the right column shows independent vowel letters.

Click on a grapheme to find other mentions on this page (links appear at the bottom of the page). Click on the character name to see examples and for detailed descriptions of the character(s) shown.

For some diphthongs ending in -j or -w, Owen indicates that phonetic sequences exist. but offers no examples. Based on other examples, it is assumed here that -j is formed using sakot+ya, and -w using sakot+wa, except where the preceding vowel sign extends below the baseline (such as for uj).

Consonant summary table

The following table summarises the main consonant to character assigments.

Columns represent high, medium, and low class, left to right.

For additional details see vowel_mappings.

Basic consonants

The lists below show consonants in the Northern Thai repertoire. The letters h, m, and l indicate the class of the consonant. This list includes some sequences to indicate high class forms when there is no single letter for that. Where 2 pronunciations are given, the first is for syllable-initial, and the second for syllable-final use.

ʨʰ is not a native Northern Thai sound, but rather associated with reading the alphabet out loud and in learned pronunciation of Pali loanwords.o,142

A few consonants have different phonetic realisations in Tai Khün, and ᨢ is not used by Tai Khün.

Special consonants

The first of these is a special-use consonant diacritic. The second two are ligatures.

1A5B represents two different functions with the same appearance. It represents ᨮ in eᩈᨱᩛᩣ᩠ᨶ sṇ̱ᵽā˖ṉ shape And it represents ᨻ in ᩋᨾᩛ ʔ̯m̱ᵽ mangoCompare with the somewhat rare subjoined form,e eg. ᨷᩢᨱ᩠ᨻᨷᩩᩁᩩᩇ b̯áṇ̱˖p̄b̯uruṣ disciple

ᩓ represents the combination ᩃᩯ, eg. ᩈᩮᩓ᩠ᩅ᩶

ᩔ represents geminated ᩈ.

Silencer

1A7A is used in Northern Thai to silence one or more characters in a word. It is not always clear which sound or sounds are cancelled. Click on the following words to see how the letters map to sounds.

ᨵᨾ᩠ᨾ᩺

ᨼᩥᩃ᩠ᨾ᩺

In Lü it is used as a final n; in Khün it is used as a final r.

Subjoined consonants

Tai Tham is unusual in that subjoined consonants do not only appear where there are consonant clusters. There is a natural tendency to attempt to stack consonants, usually 2 high, whenever possible.

1A60 is the (always) invisible character used to produce the subjoined form of a consonant, eg. compare the following:

ᨠᨠ kk [U+1A20 TAI THAM LETTER HIGH KA + U+1A20 TAI THAM LETTER HIGH KA]

ᨠ᩠ᨠ kk [U+1A20 TAI THAM LETTER HIGH KA + U+1A60 TAI THAM SIGN SAKOT​ + U+1A20 TAI THAM LETTER HIGH KA]

Sakot doesn't always kill the inherent vowel between two consonants, nor does it create conjuncts, in the sense of merged shapes, but subjoined forms of consonants typically have a different and smaller shape compared to the standard form.

Sakot can follow a vowel sign. For example, in the following word the sakot is used to position the final consonant in the syllable below the vowel sign. This is quite common.

ᩈᩣ᩠ᨾ

A subjoined consonant can also follow a digit.

᪓᩠ᨴ

Subjoined consonants are not only syllable-final consonants. The first consonant in a following syllable may also be subjoined, eg. (final r is pronounced as n).e u,654

ᨳ᩠ᨶᩫ᩻ᩁ

This list shows consonants in their normal and subjoined forms. Not all consonants traditionally have subjoined forms, but modern innovations in borrowed terminology suggest that fonts should provide them for all consonants except the old vocalic letters.u,654 You may find that the font applied here doesn't handle all combinations well.

1A7B is used in Northern Thai to identify double-acting consonants, or to indicate that a subjoined consonant begins a new syllable, eg. compare the following (where final r is pronounced as n).e

ᨳᩫ᩠ᨶᩁ tʰo˖ṉṟ tʰonra

ᨳ᩠ᨶᩫ᩻ᩁ tʰo˖ṉʻṟ tʰanon

(It is also used to repeat a word.)

Onsets

The following are used to represent the second consonant in syllable-initial clusters.

1A55 after a stop generally produces aspiration, or converts the sound to x, but it may also be pronounced -l.

ᨠᩕᩣ᩠ᨷ

ᨣᩕᩢ᩠ᨷ

1A56 is commonly not pronounced, however it is also found in the combination ᩉᩖ, which creates a high class letter with the sound l.

ᨠᩖᩣ᩶

ᩉᩖᩢᨠ

A medial -w also occurs, but there is no dedicated character for it. Instead it is produced using an ordinary WA which is subjoined using the sakot, ie. 1A60 1A45. Such clusters are generally limited to kw and xw, although some other combinations are occasionally found, though they appear to be tending to obsoletion.wnl,#Consonants

ᨣ᩠ᩅᩣ᩠ᨿ

Other syllable-initial clusters include the combination of ᩉ plus a subjoined low class consonant to make the consonant high class (see highclass). These combinations are not pronounced as multiple consonants.

Finals

Northern Thai text commonly renders syllable-final consonants using regular consonant code points (see the example just below), but sometimes special combining characters are used.

ᩑᨠ

Stacking

When regular consonants are used they are commonly subjoined, eg.

ᨠᩣ᩠ᩁ

There are, however, exceptions. For example, when preceded by a subscript vowel a final consonant may be rendered on the baseline, eg.

ᩃᩪᨠ

Northern Thai tends to add sub-base vowels below a consonant stack, whereas Khün typically shifts the vowel to the right of the stack (see fig_kiss).

show composition

ᨧ᩠ᨷᩪ

Due to font design or USE (the Universal Shaping Engine) the characters may have to be typed in an order that departs from the spoken order so that they look as expected. For example, the word in fig_kiss is stored as CCV, whereas it is pronounced CVC.

Consonant to script mapping

This section maps Northern Thai consonant sounds to common graphemes in the Lanna orthography. Sounds listed as 'infrequent' are allophones, or sounds used for foreign words, etc.

The right-hand column shows subjoined forms.

Click on a grapheme to find other mentions on this page (links appear at the bottom of the page). Click on the character name to see examples and for detailed descriptions of the character(s) shown.

Logographs

The meaning of each of the logographs is shown above. Unicode classes these symbols as punctuation.

Other features

Order of YA

A first example concerns the order of vowel components that include a subjoined YA. The following produce identical output for the multipart vowel pronounced ia in the Payap Lanna, Lamphun, and Hariphunchai fonts (but not in the Noto Sans Tai Tham font).

ᨠ᩠ᨿᩮ kia [KA + SAKOT​ + YA + E​]

ᨠᩮ᩠ᨿ kia [KA + E​ + SAKOT​ + YA]

In this case, the first alternative, which subjoins the YA with the KA and follows it with the MAI SAT vowel sign seems the more intuitive, since the diphthong produced is ia.

However, change the sound to aj and the above logic would lean towards the second of the two following encodings, which also produce identical results.

ᨠ᩠ᨿᩢ kaj [KA + SAKOT​ + YA + MAI SAT​]

ᨠᩢ᩠ᨿ kaj [KA + MAI SAT​ + SAKOT​ + YA]

This is somewhat unusual for Unicode, since it involves an invisible stacker appearing after a vowel mark (there is no other way of producing the right shape for the semivowel j).

Subjoined OA

The following 2 sequences produce identical visual results.

ᨠᩴ᩠ᩋ kɔː(?) [HIGH KA + MAI KANG​ + SAKOT​ + A]

ᨠᩬᩴ kɔː(?) [HIGH KA + VOWEL SIGN OA BELOW​ + MAI KANG​]

There appears to be some question about which is the appropriate sequence for the multipart vowel -ɔː.

Digits

Two sets of digits are in common use: a secular set (Hora) and an ecclesiastical set (Tham). European digits are also found in books. u,665

Glyph styles

In addition to the regular differences in shape of glyphs in Northern Thai and Tai Khün, the shapes of certain glyphs in Northern Thai texts may also vary, depending on the region or source.

By way of a further example, the Payap Lanna and Haripunchai fonts differ in terms of styling, but some glyphs are substantially different. The following table shows glyph shapes for various characters in both fonts.

Context-based shaping & positioning

Northern Thai text relies on rules to correctly position glyphs and shape them according to the surrounding text.

One major area where this applies is in the use of subjoined forms for consonant stacks (see clusters). Many of the subjoined forms of a letter are substantially different and/or smaller than the normal letter glyph, but the character in memory is the same.

The following is a selection of other examples of contextual shaping and positioning.

Placement of tone marks may involve special shaping and positioning. In some fonts a tone mark is displayed alongside a superscript vowel sign, rather than above it.

A number of code point sequences may be ligated by a font.

Word boundaries

Spaces separate phrases. There is no separation of individual words.

A new word may start with a subjoined consonant. Stacking is performed across word boundaries. This means that operations such as line-breaking, word highlighting, etc. have to use an orthographic syllable unit which differs from the underlying phonetic syllables.

Graphemes

tbd

Phrase & section boundaries

Northern Thai uses a variety of native punctuation, and only a couple of ASCII code points.

The following punctuation marks have "progressive values of finality".

1. ᪨
2. ᪩
3. ᪪
4. ᪫

European punctuation such as question marks and exclamation marks are also used.

᪣, ᪤, ᪥, and ᪭ are all used as section starters, sometimes in conjunction with other punctuatione, eg.

᪩᪥᪩

᪭ᩣ

To close a section, use ᪦ and/or ᪬, eg.

᪦᪦᪩

᪩᪦᪩

᪩᪦᪩᪬

᪦᪦᪬

Quotations & citations

Northern Thai texts use quotation marks around quotations. Of course, due to keyboard design, quotations may also be surrounded by ASCII double and single quote marks.

Abbreviation, ellipsis & repetition

Line breaking & hyphenation

There are no spaces between words in Northern Thai to serve as line-break opportunities. Lines must be broken at orthographic syllable boundaries. Since the onset consonant of a word or syllable may be subjoined below a previous consonant, and stacks must not be broken, orthgraphic syllable units typically don't match phonetic syllables or words.

Baselines, line height, etc.

Northern Thai uses the so-called 'alphabetic' baseline, which is the same as for Latin and many other scripts.

Northern Thai places vowel and tone marks above base characters, one above the other, and can also add combining characters below the line. It also stacks characters, though stacks are usually limited in height. The complexity of the text means that the vertical resolution needed for clearly readable Northern Thai text is higher than for English, or most Latin text. In addition,

To give an approximate idea, fig_baselines compares Latin and Northern Thai glyphs from the Payap Lanna font. The basic height of Northern Thai letters is typically around the Latin x-height, however extenders and combining marks reach well beyond the Latin ascenders and descenders, creating a need for larger line spacing.